android firebase注册表id已收到，但通知未显示在手机显示屏上

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<uses-permission android:name="android.permission.VIBRATE" />

implementation 'com.google.firebase:firebase-messaging:20.1.0'

FirebaseApp.initializeApp(this);

public class MyFirebaseMessagingService extends FirebaseMessagingService {
    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        // 处理接收到的消息
    }
}

FirebaseInstanceId.getInstance().getInstanceId()
    .addOnCompleteListener(new OnCompleteListener<InstanceIdResult>() {
        @Override
        public void onComplete(@NonNull Task<InstanceIdResult> task) {
            if (!task.isSuccessful()) {
                Log.w(TAG, "getInstanceId failed", task.getException());
                return;
            }

            // 获取注册表ID
            String token = task.getResult().getToken();

            // 将注册表ID发送到您的服务器进行处理
        }
    });